Immune Checkpoint Inhibition for Hepatocellular Carcinoma, Cholangiocarcinoma, and Combined Hepatocellular-Cholangiocarcinoma.

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a rare primary liver carcinoma that is composed of hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA). Given its low incidence, there is no standardized treatment protocol or systemic regimens. With the development of immune checkpoint inhibitors (ICIs), one of the immunotherapies that modulate the immune system by restoring antitumor immune response, studies have shown promising results for the use of ICI as systemic therapy for advanced solid tumors, including liver cancers. Moreover, prospective clinical studies displayed favorable outcomes of the use of ICIs in HCC and biliary tract cancers. Here, we review the recent evidence in application and comparison of ICIs for HCC, CCA, and cHCC-CCA as well as the future direction of systemic therapy for cHCC-CCA.